Wrap text around a Circle without deforming it. (numbers on clock)
On the surface, and for most text the Text On Curve option would work great. The clockface however is the one example where the positions of the Numerals are more important than the perfect spacing between them.

See here in green the marks where the midpoint of these Numerals would need to be to make the clock look as expected, but automated Justify  or setting the Spacing of the Word will result in an indiscriminate offset (shown by the red markers).



You can tweak the individual spaces between consecutive characters, even between a space character and a letter. This is called Kerning and it can be positive or negative. The keyboard command is Alt + Left / Right.

The technique is as follows: You place the text in edit mode while it is on the Curve, then navigate with left / right to the spaces between the Numerals, then to increase spacing you do Alt+Right, and decrease space Alt+Left.



In the End it may look something like this. (which I still think looks wonky)



Consider using a background image to help decide where on the perimeter to place these numerals. It's not trivial to get comfortable spacing (but you can copy from the masters).

Problems with this method  

I still have issues with this because the Curve is also applied between individual characters of the Numeral. You may or may not have an issue with that, but many clocks don't use that kind of Text On Curve aligning.



What I would do.

I'd do it with Sverchok (full disclosure, I coded some of Sverchok and wrote the Typography / Type Draw node):



For the Sverchok file here's a .blend of that node setup.



or


Add a Circle of the desired size. (with 12 vertices)
Add One Text Object
Give the Text Object the Center Align
Make the Circle the parent of the Text Object
Set Duplication in the Circle to Vertices and tick the Rotation box


You might get something like this:




with the Parent object (Circle) selected, press ctrl + shift + A to make the Duplicates Real. 





Still with the Parent Object (Circle) selected press U to get the Make Single User menu , choose Objects &amp; Data from this list. Now you can edit the Numerals individually :)